Low and zero energy buildings - towards green cities in Australia - - PowerPoint PPT Presentation

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Low and zero energy buildings - towards green cities in Australia - - PowerPoint PPT Presentation

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Low and zero energy buildings - towards green cities in Australia Assoc. Prof. Alistair Sproul School of PV & RE Engineering UNSW, Sydney, Australia SPREE seminar series 17 December 2015 IEA 2015 WEO Report We face a moment of

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Low and zero energy buildings - towards green cities in Australia

  • Assoc. Prof. Alistair Sproul

School of PV & RE Engineering UNSW, Sydney, Australia

SPREE seminar series 17 December 2015

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IEA 2015 WEO Report

https://www.iea.org/publications/freepublications/publication/ WEO2015SpecialReportonEnergyandClimateChange.pdf We face a moment of opportunity, but also of great

  • risk. The world is counting on the UN climate talks

in Paris later this year to achieve a global agreement that puts us on a more sustainable path. As IEA analysis has repeatedly shown that the cost and difficulty of mitigating greenhouse‐gas emissions increases every year, time is of the essence. And it is clear that the energy sector must play a critical role if efforts to reduce emissions are to succeed. While we see growing consensus among countries that it is time to act, we must ensure that the steps taken are adequate and that the commitments made are kept.

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Investment required

INDC – Intended Nationally Determined Contributions for COP21

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Energy efficiency can reduce CO2 even further

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Evolution

Sydney University “Autonomous house” in the 1970s http://larryspeck.com/2014/04/29/ autonomous‐house‐university‐of‐ sydney/ CSR house today – demonstration of how to “mainstream” an 8 star energy efficient design. http://www.csr.com.au/Our‐ Products/Documents/CSR‐House‐A4.pdf

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Poor thermal performance of buildings

Older style Australian home Typical “modern” Australian home – largest in the world If built before 2006 – no requirement in Building Code to address energy issues

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Australian homes – largest in the world

http://www.abs.gov.au/ausstats/abs@.nsf/featurearticlesbytitle/E9AC8D4A1A3D8D20C A257C61000CE8D7?OpenDocument

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Green buildings in Australia

2003 – Australian Building Code – first introduces energy requirements for residential housing. http://www.abcb.gov.au/en/work‐program/energy‐efficiency.aspx

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BCA

http://www.abcb.gov.au/en/work‐program/energy‐efficiency/residential‐housing.aspx

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Insulation requirements for homes: BCA

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http://www.build.com.au/bca-requirements-insulation

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Idealized average outside temperature - Sydney

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Results

Graph shows heat flow due to average and yearly outside temperature components. U = 0.25 W/m2K. Predominantly heat is LOST through the wall throughout the year. Daily heat flow = Maximum DAILY heat flow = AYtdTd = 200 x 0.05 x 4 = 40 W - fairly small ! True in this case as the wall is INSULATED and has mass.

 

d d d td

t ω T AY   cos

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Solar radiation incident on external wall

  • Standard “circuit analysis”.

Examine impact of one source (G) – set all

  • ther sources to zero (superposition).

G – acts as a “heat/current source” The thermal impedance from the outside surface of the wall to the inside is Zwi (i.e. 1/Yt). This is in parallel with Rso. Current divider. (Literature common nomenclature used - “surface factor”.

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Solar radiation incident on a western wall – concrete 200 mm Summer conditions

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Solar radiation incident on a western wall – concrete 200 mm Summer conditions

Heat flow into building Average 17.4 W/m2 Wall area: 200 m2 Heat load per day: 83 kWh Add external R value = 2 m2K/W Average 2.5 W/m2 Heat load per day: 12 kWh

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CRC Living Laboratory

  • Award winning 10 Star

Josh’s House in Fremantle

  • How well does the

house perform?

  • How best we can

engage people in low carbon & energy efficient living?

http://joshshouse.com.au/

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Monitoring - summer

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http://joshshouse.com.au/wp-content/uploads/2014/11/141121-JH-Year-1-Performance-Report-Design-Version.pdf

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Lochiel Park – Adelaide, South Australia

Aim is to reduce non-renewable energy consumption by 66% and GHG emissions by 74% (measured against Adelaide average).

http://www.greenwayarchitects.com.au/lochiel‐ park‐affordable‐housing/

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Lochiel Park

Comparisons of Lochiel Park (LP) house normalised total energy consumption against a sample of Mawson Lakes (ML) households, and both state (SAAVG) and national (AUSAVG) averages for delivered annual energy

50 100 150 200 250 300 350 400 LP (2011‐12) LP (2012‐13) ML (2002‐03) SA AVG (2010‐11) AUS AVG (2010‐11)

Average Delivered Annual Energy per household [MJ/m2]

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http://energiesprong.nl/transitionzero/

  • Energiesprong brokered a deal between

housing associations and builders to refurbish 111,000 houses to Net Zero Energy (E=0) levels in the Netherlands. E=0 means, annually a house does not consume more energy for heating, hot water, lights and appliances than it

  • produces. The refurbishments are

financed by the energy cost savings; a refurbishment is executed within 10 days and comes with a 30-year energy performance warranty from the builder.

  • Energiesprong’s approach is based on
  • rganizing massive demand for a Net

Zero Energy (E=0) refurbishment proposition, making financers and governments tune their financing

  • fferings and regulations towards this

product and challenging the construction sector to start an ambitious innovation process to deliver the proposition. The massive demand, the security that there will be financing and an enabling regulatory environment de-risks the innovation investment for the builders.

Making Net Zero Energy refurbishments a market reality

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BEFORE & AFTER https://www.flickr.com/photos/111630915@N04/11419884295/in/set- 72157638726631756

  • Public housing. Typical renovation costs about 50,000 to 60,000 Euros per

dwelling, no cost to occupants, renovations completed in 10 days!

  • Additional loan repayments covered by energy bills.
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Residential electrical energy usage Sydney : SGSC data (2012 – 2013)

Survey and data for ~3000 houses/units. Average usage ~ 19 kWh/day per household (~ 7 tonnes CO2 per year/household) Maximum usage observed: 125 kWh/day

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Modelled results

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Pool & HVAC ownership

“Pool pump” ownership is a significant indicator of household electricity demand. About 15% of sampled households had a pool (and hence pool pump) and the annual average daily electricity demand of these households (31.2 kWh) was 93% higher than those without (16.9 kWh). Almost three quarters of the surveyed households have “Air- conditioning” systems installed in their home, and primarily are smaller split systems (70%) or ducted systems (26%). There is a clear difference in daily electricity demand between households with and without air-conditioning systems, and, for those that do, by type

  • f system: households with “Ducted” air conditioning (27.3 kWh)

use on average 79% more electricity than households with no air- conditioning – “NONE”(15.2 kWh,  = 10.1 kWh); while households with a “Split System”(20.4 kW h,  = 10.4 kW h) on average consume 34% more electricity than households with no air- conditioning.

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Correlation between HDD/CDD and electricity usage for Sydney (2012 – 2013)

Heating demand is a major driver of electricity usage over the year Cooling demand drives spikes in electricity usage in summer

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29 INDOOR UNIT FTXZ25NV1B FTXZ35NV1B FTXZ50NV1B OUTDOOR UNIT RXZ25NV1B RXZ35NV1B RXZ50NV1B Rated Capacity Cool (kW) 2.5 3.5 5 Heat (kW) 3.6 5 6.3 Capacity Range Cool (kW) 0.6-3.9 0.6-5.3 0.6-5.8 Heat (kW) 0.6-7.5 0.6-9.0 0.6-9.4 Indoor Airflow Rate (Hi) Cool (I/s) 177 203 250 Heat (I/s) 195 221 240 Star Ratings Cool 7 5.5 3.5 Heat 7 5.5 4.5 Power Input (Rated) Cool (kW) 0.42 0.68 1.18 Heat (kW) 0.62 0.99 1.37 E.E.R./C.O.P. Cool/Heat 5.95/5.81 5.15/5.05 4.24/4.60 A.E.E.R./A.C.O.P. Cool/Heat 5.90/5.77 5.12/5.03 4.23/4.59

http://www.daikin.com.au/us7 http://reg.energyrating.gov.au/comparator/product_types/64/search/ Most efficient reverse cycle AC currently available in Australia

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http://astralpool.com.au/products/viron-p300-pump-0

Multispeed and variable speed pumps now in the Australian market Up to 9 star efficiency!

Three speed pump – significant energy savings. Reduce energy by more than 5 kWh/day

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Pool heating – very energy intensive

http://www.ausgrid.com.au/~/media/Files/Customer%20Services/Homes/Energ y%20Efficiency/Ausgrid%20Swimming%20Pool%20brochure%202015.pdf

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Solar pool heating: initial results

Average daily pump energy required: 0.9 kWh/day Solar heating system using a Viron p280 – 3 speed pump

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Heat pump hot water

https://www.sanden-hot-water.com.au/about-the-eco Sanden: They use a CO2 refrigerant, COP = 4.5

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Instantaneous gas

Pros: no storage losses, unlimited hot water! Cons: Gas costs Sydney 3.5 c/MJ - 12.6 c/kWh. Efficiency 60% - condensing systems over 90%.

Running costs for hot water systems in Sydney

Solar Hot Water

Pros: ~80% solar fraction, can be backed up by off-peak. Cons: Back up required, better if forecasting is available. Capital costs higher than conventional

Heat pump

Pros: ~80% ambient fraction (COP = 4.5!), can be backed up by off-peak or PV (15 c/kWh) (thermal storage – delivered cost 3.3 c/kWh). Cons: Back up required, better if forecasting is available. Capital costs higher than conventional

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6 Star commercial and beyond

CH2 – 6 star Green Star - Melbourne TETB UNSW – 6 star Green Star - Sydney Pixel building. Highest LEED score world-wide. Melbourne 1 Bligh St – 6 star Green Star

  • Sydney
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5 star residential

Central Park – 5 star NatHERS residential

  • Sydney

Haymarket Metro Plaza – 5 star NABERs and Green Star Multi-unit Residential & Retail - Sydney

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UNSW Tyree Energy Technology Building - 6 star Green Star, 150 kWp PV array

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http://www.facilities.unsw.edu.au/campus-development/sustainability- campus/greensense-live-energy-project

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UNSW TETB Electricity - Mar 4 – 10,

2013

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Conclusions

  • Residential energy efficiency – significant resource that could be “mined” if we

wanted to cost effectively reduce household electricity bills and reduce carbon emissions.

  • 70% reductions have been modelled and demonstrated – typically ~8 year

payback.

  • Thermal performance of buildings is poor in Australia – can we retrofit better

envelopes cost effectively – particularly insulate walls, improve glazing and shading?

  • HVAC systems are improving all the time – COPs approaching 6 but we need

more efficient homes OR large more efficient HVAC units.

  • PV and high COP HVAC – precool buildings on hot days – ramp down demand

and help reduce evening peak.

  • Can we find ways to improve existing ducted systems? Zoning? Better insulation

for ducting, minimizing heat gains into HVAC ducting particularly during peak.

  • Pools – lets’ not avoid peak by simply shifting when pool pumps are running –

variable speed or multiple speed pumps can lower energy significantly (and quietly!)

  • PV – heat pump hot water- lower running costs than gas (but not off peak heat

pump). Possibly lower life cycle costs than solar thermal hot water? Thermal storage for PV!

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Acknowledgements

  • This research was funded by the CRC for Low Carbon Living Ltd supported

by the Cooperative Research Centres program, an Australian Government initiative.

  • There are many more projects currently underway in this space - please

see: http://www.lowcarbonlivingcrc.com.au/

  • I would also like to acknowledge all of my colleagues and students who have

been involved in various elements of the research described here particularly: Hua Fan, Iain MacGill, Jianzhou Zhang and Ted Spooner.